weather; *clear -> this is the optimal weather, it can dry up the ground if it is mudddy or frozen, all operate at full capacity *overcast -> spotting is reduced *rain -> aerial units cannot attack nor be attacked, chance to turn the ground into mud *snow -> aerial units cannot attack nor be attacked, chance to turn the ground into frozen *muddy ground -> movement is slowed for all ground units and fuel consumption increased *frozen ground -> rivers and lakes freeze and can be moved across